Abstract
The effect of Ar pressure during sputter-deposition of Co-Cr films on their magnetic properties and microstructures were studied in a wide pressure range (0.2-100 Pa) far beyond conventional sputterings. Films with higher coercivity than 600 Oe were obtained by increasing only the sputtering pressure up to three orders of magnitude higher than conventional ones even at room temperature, where any other special method such as reactive sputtering was not used. The films exhibited a typical clear columnar structure with physically separated grain boundaries. It was concluded that the high coercivity was attributed to the perpendicular anisotropy due to mainly a shape effect of the columnar grains and to the isolation effect between magnetic particles associated with the development of the physical separation between the columnar grains. The contribution fraction of the crystalline anisotropy to the total perpendicular anisotropy was estimated to be as low as about 20%. The performed ultra high Ar pressure deposition will be a powerful means for realization of a low temperature sputter-deposition for perpendicular recording media.
